I have used the Fertile Focus for the last 5 years. Just bought my second one. We have used this as our form of natural Family Planning. I don't like the idea of putting toxins into my body for contraceptives and the charting went over my head! This is right up my alley. It is easy to use. Easy to interpret. Inexpensive and discreet. Has worked very well for us. Highly recommended!

Took me a while to figure out how to focus this thing. The twisty part of the lens was so tight I couldn't do it by hand and was afraid to break it. Finally I grabbed the flat part w wrench and was able to loosen it and can now twist and focus easily. Sure enough I can see a ferning pattern clear as day. It was really exciting since I have a hard time catching an LH surge. This is a neat little device. However if they were going for "discrete lipstick case", maybe don't have a label that says "ovulation microscope" on it!

As a biologist, I find this to be a really interesting, reusable piece of fertility tracking equipment. However, upon searching peer-reviewed research, I cannot find a single paper that shows the correlation between fertility and salinity in the female body.
That being said, I think it does work - when you know what you're doing.
I used this alongside some LH tests, and for 2 cycles (which I know is not enough for a legitimate study), I have seen pre-ferning starting about 1 week before an LH surge and full ferning starting approximately 24-48 hours before an LH surge and ending 24-48 hours after.
I truly hope I'm not using this long enough to give you a full year's worth of results.
We are not pregnant at this time, and I can't blame any external equipment for that.
Some takeaways:
Do not use this product if you
* Do not like touching your own spit. There is literally no way to put it on the lens if you don't put your finger in your mouth. My method is to put my tongue on the roof of my mouth and scoop some from the saliva wells underneath. I would like to see the manufacturer put a mini pipette in the package that I could suck the saliva out and tap bubbles out. Now that I've thought of that, I'm gonna find one.
* Are unaware or unwilling to learn how to focus a microscope. The product is, before anything else, a microscope. In fact, I've wondered if I could do the same thing on my table microscope, but this is way easier to keep next to my BBT Thermometer. You'll need to refocus it every time because your saliva will be a different density. The outer ring moves, and can sometimes be very difficult to use.
* Are uncomfortable looking into a bright light. Again, microscope. You put your eye up to the ocular lens and shine a light to see your ferns (or just random spots when you're not ferning)
* Don't have a place for it to dry. I live in a wet climate. Here's how I use this: I take my BBT, get up, swipe saliva out of my mouth, place it on the bottom of the lens, place the top (eye piece) of the lens on my dresser, place the cap over the lens, allow to sit until bedtime. There are days when I get too much saliva that it still doesn't dry. In those cases, I'll let it dry overnight and look at my ferning pattern before I start the process over. Once I've seen the patterns, I dampen the bottom of the lens and wipe it with a soft cloth (usually a t-shirt, if I'm going to be honest). If you live in a dry environment, I would assume that this goes better, but you still will need to leave the lens undisturbed for a minimum of 5-10 minutes according to directions. If you don't have a space for that, this is going to be a true pain.
* Don't have the ability to find out your cycle rhythm, at least for a couple of months. I used this for 3 months before I bought LH strips, and the results seemed kind of random. I'd get partial ferning for a couple of days, it'd go away suddenly, then I'd get a couple days of full ferning. Purchasing a package of LH strips has made me feel much more confident about potentially using the Fertile Focus by itself, and I wish I'd gotten them to start with. Knowing the full rhythm chemically, hormonally, and biologically to begin with would have made everything a lot easier.

So, is this the product for you? Well, I don't know. I'm not sure I'd use it as my sole source of fertility planning, but I think it's definitely something you can add to your repertoire for more data. I'm a huge data fan.

Amazon says I purchased this jan 2008. The battery died while TTC our third. Now I just hold it up to the light in the bathroom. I clean it off with my tshirt. No scratches and still works perfectly. My 3yo got ahold of it and dunked it in the water playing in the sink, which must have loosened the glue because it came apart and it looks like I'll be able to replace the battery...not sure how the water may have damaged though. I'm surprised at all the negative reviews. I would hazard a guess that people aren't following the directions. It does exactly what it's supposed to do. And lasted quite a long time...about 6 years! I have long cycles and didn't use it daily, only around ovulation, but I think that's a pretty good battery life!

Worked fine until the battery died. I don't care what anyone says, the battery in my FertileFocus is not replacable. Had I known this, it would've been a dealbreaker. I followed the instructions given on how to replace it and nearly broke the thing in my attempt. Now I have to spend $50 on a better brand. FertileFocus suppliers: if the battery is truly replacable on EVERY microscope, put out a video instructing how to replace it.